Seminconductor device

ABSTRACT

The present invention provides a signal transmitting/receiving method comprising: disposing a ferromagnetic film between a semiconductor device having an inductor and an external device which includes an external inductor provided in a position corresponding to the inductor of the semiconductor device; disposing the inductor and the external inductor so as to face each other via the ferromagnetic film therebetween; and in a state in which the inductor and the external inductor face each other, transmitting and receiving the signals between the inductor and the external inductor by electromagnetic induction.

This application is based on Japanese Patent Application No. 2008-313316filed in Japan.

BACKGROUND OF THE INVENTION

The present invention relates to a signal transmitting/receiving method,a semiconductor device manufacturing method, a semiconductor device, anda tester.

In order to test an internal circuit of the semiconductor device in itswafer state, there have been attempts to probe a pad on a chip surfaceof the semiconductor device for supplying an electric power or totransmit and receive signals for observation. Such techniques have beendisclosed in the following Patent Documents.

Japanese Patent Laid-Open No. 2005-30877 discloses a technique forperforming a test by mounting a test circuit and a wirelesscommunication circuit in a semiconductor integrated circuit device, andusing wireless signals to control the test circuit.

Japanese Patent Laid-Open No. 2003-344448 discloses a voltage probe chiphaving a sensor electrode which is disposed facing a signal line to bemonitored on a semiconductor chip so as to detect a voltage change ofthe signal line as an induced voltage caused by electrostatic induction.

However, the inventors have found the following problems. There areproblems in that the pad is damaged by a tester needle during a probetest, causing a connection failure later when the pad is bonded, or thepad is scratched to generate scrap materials causing contamination, andthe like. There is another problem in that the more the chip size isreduced and the more the number of pads per chip is increased, the morethe pad size and the inter-pad pitch is reduced, and thereby the moredifficult it is to provide a well electrical connection by contacting alarge number of probe needles corresponding to a large number of pads.In order to prevent such problems, it is preferable to transmit andreceive signals to and from the internal circuit without using the probeneedles.

However, in order to obtain signals having intensity enough to transmitand receive the signals by electromagnetic induction using an inductor,it is necessary to increase the inductor size, which increases the areanecessary to provide the inductors. In particular, in order to provide alarge number of inductors corresponding to a large number of pads, thearea necessary to provide the inductors is greatly increased.

SUMMARY

The present invention provides a signal transmitting/receiving methodcomprising: disposing a ferromagnetic film between a semiconductordevice having an inductor and an external device which includes anexternal inductor provided in a position corresponding to the inductorof the semiconductor device; disposing the inductor and the externalinductor so as to face each other via the ferromagnetic filmtherebetween; and in a state in which the inductor and the externalinductor face each other, transmitting and receiving the signals betweenthe inductor and the external inductor by electromagnetic induction.

Further, the present invention provides a semiconductor devicemanufacturing method comprising: disposing a semiconductor device whichincludes a first insulating film which includes a transistor on asubstrate and a second insulating film which is provided on the firstinsulating film and includes an inductor and an external device whichincludes an external inductor provided in a position corresponding tothe inductor of the semiconductor device so as to face each other; anddisposing a ferromagnetic film which includes ferromagnetic fineparticles at least between the inductor of the semiconductor device andthe external inductor of the external device; and disposing the inductorand the external inductor so as to face each other via the ferromagneticfilm therebetween; and in a state in which the inductor and the externalinductor are made to face each other, transmitting and receiving signalsbetween the inductor and the external inductor by electromagneticinduction.

This configuration can maintain as small an area as necessary to providethe inductors and can well transmit and receive signals byelectromagnetic induction.

The above configuration can increase the inductor coupling factorbetween the inductors formed in the semiconductor device and theexternal inductors when signals are transmitted and receivedtherebetween by electromagnetic induction. Thereby, this configurationallows an inductor with a smaller size to well transmit and receivesignals by electromagnetic induction. For this reason, thisconfiguration can maintain as small an area as necessary to provide theinductors and can well transmit and receive signals by electromagneticinduction.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the presentinvention will be more apparent from the following description taken inconjunction with the accompanying drawings, in which:

FIGS. 1A to 1C each is a process cross-sectional view illustrating aprocedure for manufacturing a semiconductor device in accordance with anembodiment of the present invention;

FIGS. 2A to 2D each is a process cross-sectional view illustrating aprocedure for manufacturing a semiconductor device in accordance with anembodiment of the present invention;

FIG. 3 is a plan view of the substrate illustrated in FIG. 1;

FIG. 4 is an enlarged view of FIG. 3;

FIG. 5 is an enlarged sectional view of FIG. 2A;

FIG. 6 is an enlarged sectional view of FIG. 2B;

FIG. 7 is a plan view illustrating an example of a semiconductor chipforming region of the semiconductor device in accordance with anembodiment of the present invention;

FIG. 8 is a plan view illustrating another example of the semiconductorchip forming region of the semiconductor device in accordance with anembodiment of the present invention;

FIG. 9 is a sectional view illustrating a configuration of a tester inaccordance with an embodiment of the present invention; and

FIG. 10 is a sectional view illustrating another example of thesemiconductor device in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention will be now described, herein with reference toillustrative embodiments. Those skilled in the art will recognize thatmany alternative embodiments can be accomplished using the teachings ofthe present invention and that the invention is not limited to theembodiments illustrated for explanatory purposes.

First Embodiment

Hereinafter, embodiments of the present invention will be described byreferring to drawings. Note that throughout the drawings, like referencecharacters refer to like elements and the duplicate description isomitted as needed. In the present embodiment, assuming that the externaldevice is a tester, the following description will use an example inwhich when a test is conducted on an internal circuit in a chip formingregion of the semiconductor device in its wafer state, various testsignals are transmitted and received to and from the tester byelectromagnetic induction.

FIGS. 1 and 2 each is a process cross-sectional view illustrating aprocedure for manufacturing a semiconductor device in accordance with anembodiment of the present invention.

The semiconductor device 100 includes a substrate 102 (wafer). Accordingto the present embodiment, an inductor forming region 110 in which aplurality of inductors are formed is provided on one surface of thesubstrate 102. Signals are transmitted and received between the aboveconfigured semiconductor device 100 and a tester 200 which includes aplurality of external inductors each of which is provided in a positioncorresponding to each inductor in the semiconductor device 100, andtransmits and receives the signals by electromagnetic induction.

FIG. 3 is a plan view of the substrate 102 illustrated in FIG. 1. FIG. 4is an enlarged view of FIG. 3. FIG. 3 illustrates only the outer edge ofthe substrate 102. As illustrated in FIG. 4, the one surface of thesubstrate 102 includes a plurality of semiconductor chip forming regions104 and scribe line regions 106 each of which is provided on the outercircumference of a semiconductor chip forming region 104. FIG. 4illustrates four semiconductor chip forming regions 104 and an alignmentmark 108 between them in the scribe line region 106. The semiconductorchip forming region 104 is a region which will be a semiconductor chipafter dicing.

An internal circuit 118, a plurality of inductors 114, and a pluralityof bonding pads 116 are provided in each semiconductor chip formingregion 104 of the semiconductor device 100. The bonding pad 116 is a padon which wire bonding is performed later. The bonding pad 116 iswire-connected to the internal circuit 118, the wire of which isconnected to the inductors 114. The inductor 114 can be provided as analternative to the pad provided for probing when a test is performed onan internal circuit of a conventional semiconductor device in its waferlevel. The inductor 114 may be provided or may not be provided in allthe wires connecting between the bonding pad 116 and the internalcircuit 118. In addition, although not illustrated, the semiconductordevice 100 includes a plurality of conversion circuits providedcorresponding to each inductor 114. Moreover, although not illustrated,the semiconductor device 100 can include a power circuit.

Note that the inductors 114 are provided on the surface of thesemiconductor device 100 so as to transmit and receive signals to andfrom an external device. In addition, the bonding pads 116 are alsoprovided on the surface of the semiconductor device 100 so as to performwire bonding later. Note that the surface of the inductor 114 may becovered with a film such as a passivation film to such an extent thatthe film does not affect the process of transmitting and receivingsignals by electromagnetic induction. Moreover, the bonding pad 116 isformed in a region not to interrupt communication between the inductors114 and the external device. Here, the region not to interruptcommunication indicates a case in which the inductor 114 and the bondingpad 116 are formed in a different region when viewed from above in FIG.4. Note that the inductor 114 and the bonding pad 116 shall be slightlyoverlapped.

On the other hand, the conversion circuit serves only to convert thesignals that the inductors 114 transmit and receive to and from theexternal device, and thus needs not be provided on the surface of thesemiconductor device 100. For this reason, the conversion circuits canbe provided so as to be overlapped with the inductors 114 in thelaminating direction of the semiconductor substrate, and thus cansuppress an increase in size of the semiconductor device 100. Forexample, each conversion circuit is provided in a layer under itscorresponding inductor 114. Each inductor 114 is electrically connectedto the internal circuit 118 via its corresponding conversion circuit.The conversion circuit performs modulation and demodulation on thesignals transmitted and received between the internal circuit 118 andthe external device. In addition, each bonding pad 116 is alsoelectrically connected to the internal circuit 118.

Although not illustrated here, the internal circuit 118 can include aplurality of transistors corresponding to the plurality of inductors114. One end of each of the source and the drain of a transistor isconnected to ground and the other end thereof is connected to a powercircuit via a power supply line. In addition, the gate of eachtransistor is connected to each inductor 114 via each conversioncircuit. Further, the gate of each transistor is also connected to eachbonding pad 116. Note that a configuration may be made such that an I/Obuffer circuit is included between the transistor, the bonding pad 116,and the conversion circuit.

Now, going back to FIGS. 1 and 2, the description continues with theprocedure for manufacturing the semiconductor device in accordance withthe present embodiment.

As illustrated in FIG. 1A, the ferromagnetic film 130 is formed on theinductor forming region 110 formed on one surface of the substrate 102of the semiconductor device 100 described above. The ferromagnetic film130 can be a tape containing ferromagnetic fine particles in aninsulating film (polymer) such as polyester. Here, the ferromagnet canbe a metal such as Fe, Co, and Ni or their alloy. The ferromagnetic film130 can be about as thick as from 20 μm to 0.25 mm. The ferromagneticfilm 130 can be formed on the semiconductor device 100, for example, inthe following procedure. First, an adhesive such as a water-soluble glueis applied to the entire surface of the ferromagnetic film 130, and theferromagnetic film 130 is disposed in such a manner that the one surfaceon which the adhesive is applied is in contact with the one surface ofthe substrate 102 on which the inductor forming region 110 is formed.Then, the ferromagnetic film 130 is pressed and adhered onto theinductor forming region 110 by a roller (not illustrated) or the like.

Then, for example, the ferromagnetic film 130 is cut along thecircumferential portion of the substrate 102 by contacting the cutter150, which is a circumferential cutter, against the edge of thesubstrate 102. Thereby, the ferromagnetic film 130 having the same sizeof the substrate 102 can be formed on the substrate 102 (FIG. 1B).

Next, the bottom surface opposite to the one surface of the substrate102 is ground by a machine such as a back grinder to form the substrate102 having a predetermined thickness. For example, the thickness of thesubstrate 102 can be about from 200 μm to 400 μm (FIG. 1C).

Subsequently, signals are transmitted and received between externalinductors of the tester 200 and inductors in the inductor forming region110 of the semiconductor device 100. According to the presentembodiment, the tester 200 includes a plurality of test chips 201 (chipsfor performing a test). Each test chip 201 is formed to a sizecorresponding to each semiconductor chip forming region 104 of thesemiconductor device 100.

First, the semiconductor device 100 is mounted on a mounting base 152,and the tester 200 is placed closer to the semiconductor device 100.Then, signals are transmitted and received between the externalinductors of the tester 200 and the inductors in the inductor formingregion 110 of the semiconductor device 100 (FIG. 2A and FIG. 2B).

FIG. 5 and FIG. 6 each is an enlarged sectional view of FIG. 2A and FIG.2B respectively. Here, each figure partially illustrates one of thesemiconductor chip forming region 104 (see FIG. 4) of the semiconductordevice 100 and one of the test chips 201 of the tester 200.

The inductor forming region 110 of the semiconductor device 100 has aninsulating film 112 provided on the substrate 102 and a plurality ofinductors 114 provided on one surface of the insulating film 112opposite to a surface facing the substrate 102. In addition, althoughnot illustrated, the bonding pads 116 are also provided on one surfaceof the insulating film 112. That is, according to the presentembodiment, the ferromagnetic film 130 is also provided on the bondingpads 116. The test chip 201 of the tester 200 includes a test substrate202 and a plurality of external inductors 204 each provided in aposition corresponding to the plurality of inductors 114 of thesemiconductor device 100.

Here, the insulating film 112 includes an insulating layer 165 whichincludes transistors 168 constituting circuits such as an internalcircuit, a conversion circuit, and a power circuit; and an insulatinglayer 166 which mainly includes wires. Both insulating layers 165 and166 may be formed of a plurality of insulating films and each insulatinglayer has wires required for circuit configuration therein. The inductor114 is formed in the uppermost surface layer of the insulating layer166; and the bonding pad 116 is formed in the uppermost surface layer ofthe insulating layer 166 or on the insulating layer 166, for example.

First, the tester 200 is placed closer to the semiconductor device 100in such a manner that each external inductor 204 of the tester 200 faceseach inductor 114 of the semiconductor device 100. At this time, theferromagnetic film 130 is disposed between each inductor 114 of thesemiconductor device 100 and each external inductor 204 of the tester200; and each inductor 114 and each external inductor 204 are disposedfacing each other via the ferromagnetic film 130 therebetween. Moreover,here, each inductor 114 and each external inductor 204 can be disposedfacing each other in contact with the ferromagnetic film 130. Here, theferromagnetic film 130 can also be made to function as a cushioningmaterial. Moreover, the ferromagnetic film 130 can be configured to havean approximately equal film thickness entirely. By doing so, eachinductor 114 and each external inductor 204 can be stably spaced atconstant intervals.

In this state, a radio wave having a predetermined frequency isoutputted from each external inductor 204 of the tester 200 to thesemiconductor device 100. Here, a test signal and the like are outputtedfrom the external inductor 204.

The inductor 114 of the semiconductor device 100 converts the signaloutputted from the external inductor 204 to an AC electrical signal. Theconversion circuit demodulates the AC electrical signal converted by theinductor 114 and supplies it to the internal circuit 118. On the otherhand, when a signal is outputted from the semiconductor device 100 tothe tester 200, the conversion circuit modulates the electrical signalsupplied from the internal circuit 118 and supplies it to the inductor114. The inductor 114 outputs the modulated signal as a radio wave tothe corresponding external inductor 204 of the tester 200. In thismanner, signals are transmitted and received between the semiconductordevice 100 and the tester 200.

After the process of transmitting and receiving signals between thesemiconductor device 100 and the tester 200 is completed, theferromagnetic film 130 is removed. The process of removing theferromagnetic film 130 can be performed in the following procedure.First, in a tape peeling device (not illustrated), the substrate 102 ofthe semiconductor device 100 is fixed by a vacuum chuck. In this state,a peeling tape 140 is placed in contact on the ferromagnetic film 130 soas to peel the ferromagnetic film 130 (FIG. 2C). Then, the peeling tape140 is peeled off from the semiconductor device 100 together with theferromagnetic film 130 (FIG. 2D). Subsequently, pure water, an organicsolvent, or the like is used to clean the semiconductor device 100 anddry it. Thus, the above process completes the wafer test.

Subsequently, for example, the semiconductor device 100 is cut along thescribe line region 106 to make each semiconductor chip forming region104 into a chip. Then, a semiconductor chip can be formed by connectingeach bonding pad 116 of the each semiconductor chip forming region 104to an external terminal with a bonding wire, or the like.

According to the present embodiment, when signals are transmitted andreceived between the external inductors 204 of the tester 200 and theinductors 114 of the semiconductor device 100 by electromagneticinduction, the bonding pad is provided in a region not to interrupt thecommunication to and from the external device, and thus can increase theinductor coupling factor therebetween. The inductor coupling factor canfurther increase by placing the ferromagnetic film 130 between theexternal inductors 204 and the inductors 114 of the semiconductor device100. Thereby, this configuration allows an inductor with a smaller sizeto well transmit and receive signals by electromagnetic induction. Forthis reason, this configuration can maintain as small an area asnecessary to provide the inductors and can well transmit and receivesignals by electromagnetic induction.

Moreover, the ferromagnetic film 130 can also be made to function as acushioning material. Therefore, the external inductors 204 of the tester200 and the inductors 114 of the semiconductor device 100 can be placedin contact with the ferromagnetic film 130. By doing so, each inductor114 and each external inductor 204 can be stably spaced at constantintervals.

Second Embodiment

According to the present embodiment, a configuration may be made in sucha manner that after the process of transmitting and receiving thesignals is completed, the ferromagnetic film 130 remains partially onthe semiconductor device 100.

FIG. 7 is a plan view illustrating an example of the semiconductor chipforming region 104 (see FIG. 4) of the semiconductor device 100 inaccordance with the present embodiment. In this example, theferromagnetic film 130 is not formed selectively only on a region of thesemiconductor device 100 where the bonding pads 116 are formed. Forexample, the ferromagnetic film 130 can be configured to have an openingportion 132 so as to expose the bonding pads 116. By doing so, eachbonding pad 116 can be connected to an external terminal with a bondingwire with the ferromagnetic film 130 left as is.

Thus configured ferromagnetic film 130 can be obtained in such a mannerthat for example, after the ferromagnetic film 130 is formed on theentire surface of the semiconductor device 100, the ferromagnetic film130 is removed selectively to form the opening portion 132. Theselective removal of the ferromagnetic film 130 can be performed, forexample, by wet etching using photoresist as a mask. Here, for example,the ferromagnetic film 130 can be formed in such a manner that after amulti-layered structure of the semiconductor device is formed, aferromagnet is mixed into a passivation film formed on the upper surfacethereof. In this case, the selective removal of the ferromagnetic film130 can be performed, for example, by wet etching using photoresist as amask. The selective removal of the ferromagnetic film 130 may beperformed either before or after signals are transmitted and receivedbetween the external inductors 204 of the tester 200 and the inductors114 of the semiconductor device 100.

FIG. 8 is a plan view illustrating another example of the semiconductorchip forming region 104 (see FIG. 4) of the semiconductor device 100 inaccordance with the present embodiment. In this example, theferromagnetic film 130 is formed selectively only on a region of thesemiconductor device 100 where the inductors 114 are formed. Note thathere, for the purpose of the description, the inductors 114 are alsoillustrated, but actually the inductors 114 are covered with theferromagnetic film 130. Such a configuration also allows the bondingpads 116 to be exposed, and thus each bonding pad 116 can be connectedto an external terminal with a bonding wire with the ferromagnetic film130 left as is.

Thus configured ferromagnetic film 130 can be obtained in such a mannerthat for example, after the ferromagnetic film 130 is formed on theentire surface of the semiconductor device 100, the ferromagnetic film130 is removed selectively. In this case, the selective removal of theferromagnetic film 130 can also be performed, for example, by wetetching using photoresist as a mask. Here, for example, theferromagnetic film 130 can be formed in such a manner that after amulti-layered structure of the semiconductor device is formed, aferromagnet is mixed into a passivation film formed on the upper surfacethereof. In this case, the selective removal of the ferromagnetic film130 can also be performed, for example, by wet etching using photoresistas a mask. The selective removal of the ferromagnetic film 130 may beperformed either before or after signals are transmitted and receivedbetween the external inductors 204 of the tester 200 and the inductors114 of the semiconductor device 100.

The present embodiment can also provide the same effect as the firstembodiment.

Third Embodiment

According to the present embodiment, the ferromagnetic film 130 can beconfigured to be provided on the tester 200 side.

FIG. 9 is a sectional view illustrating a configuration of the tester200 in accordance with present embodiment. Here, the tester 200 includesthe ferromagnetic film 130 formed on the surface of the externalinductors 204. Such a configuration can also provide the same effect asthe first embodiment and the second embodiment. Alternatively, aconfiguration may be made such that two ferromagnetic films 130 areprovided one on the tester 200 side and one on the semiconductor device100 side.

Hereinbefore, the embodiments of the present invention have beendescribed by referring to drawings, but these embodiments are examplesof the present invention and various configurations other than the abovecan be adopted.

In the above embodiments, the procedure for grinding the bottom surfaceof the substrate 102 described by referring to FIG. 1C may be omitted.FIG. 10 is a sectional view illustrating the semiconductor device 100corresponding to FIG. 2B in this case. In this case, like the oneillustrated in FIG. 2, signals can also be transmitted and receivedbetween the semiconductor device 100 and the tester 200.

Further, the above embodiments have illustrated the example in which thetester 200 has a plurality of test chips 201 corresponding to the numberof semiconductor chip forming regions 104 of the semiconductor device100, but the tester 200 may be configured to include the number of testchips 201 corresponding to only a part of the semiconductor chip formingregions 104 of the semiconductor device 100. In this case, a test can beperformed in series on each semiconductor chip forming region 104 of thesemiconductor device 100 by shifting the tester 200.

Moreover, the above embodiments have illustrated the example in whichthe test is performed on the internal circuit of the chip forming regionof the semiconductor device in its wafer state. However, the presentinvention can be applied to an example in which after the chip formingregion is cut into a chip, a test is performed on the internal circuitfor each semiconductor chip.

Further, the ferromagnetic film 130 can be used as an independent sheetwithout being formed on the semiconductor device 100 or on the tester200. In this case, when signals are transmitted and received between thesemiconductor device 100 and the tester 200 by electromagneticinduction, the ferromagnetic film 130 can be disposed between theinductors 114 of the semiconductor device 100 and the external inductors204 of the tester 200.

It is apparent that the present invention is not limited to the aboveembodiments and descriptions, but may be modified and changed withoutdeparting from the scopes and sprits.

1. A signal transmitting/receiving method comprising: disposing aferromagnetic film between a semiconductor device having an inductor andan external device which includes an external inductor provided in aposition corresponding to the inductor of the semiconductor device;disposing the inductor and the external inductor so as to face eachother via the ferromagnetic film therebetween; and in a state in whichthe inductor and the external inductor face each other, transmitting andreceiving the signals between the inductor and the external inductor byelectromagnetic induction.
 2. The signal transmitting/receiving methodaccording to claim 1, wherein in disposing the inductor and the externalinductor so as to face each other, each of the inductor and the externalinductor is disposed so as to be in contact with the ferromagnetic film.3. The signal transmitting/receiving method according to claim 1,wherein the semiconductor device further includes a substrate and aninternal circuit provided in the substrate; and the inductor is providedto be electrically connected to the internal circuit, and the signaltransmitted and received between the external inductor and the inductoris a test signal for testing the internal circuit.
 4. A semiconductordevice manufacturing method comprising: disposing a semiconductor devicewhich includes a first insulating film which includes a transistor on asubstrate and a second insulating film which is provided on the firstinsulating film and includes an inductor and an external device whichincludes an external inductor provided in a position corresponding tothe inductor of the semiconductor device so as to face each other;disposing a ferromagnetic film which includes ferromagnetic fineparticles at least between the inductor of the semiconductor device andthe external inductor of the external device; disposing the inductor andthe external inductor so as to face each other via the ferromagneticfilm therebetween; and transmitting and receiving signals between theinductor and the external inductor by electromagnetic induction in astate in which the inductor and the external inductor are made to faceeach other.
 5. The semiconductor device manufacturing method accordingto claim 4, wherein before the inductor and the external inductor aredisposed so as to face each other, the ferromagnetic film is formed onat least the inductor of the semiconductor device.
 6. The semiconductordevice manufacturing method according to claim 4, wherein thesemiconductor device further includes a bonding pad provided on thesecond insulating film, and after the signal is transmitted andreceived, the bonding pad and an external terminal are connected with abonding wire.
 7. The semiconductor device manufacturing method accordingto claim 6, wherein in disposing the ferromagnetic film, theferromagnetic film is also formed on the bonding pad, and after thesignal is transmitted and received, the ferromagnetic film formed on atleast the bonding pad of the semiconductor device is removed.